More android.util in Ravenwood, supported by CTS.

Carry over some existing tests from frameworks/base/ and get them
compiling against `current-test` so that CTS can verify these
public APIs, paving the way for them to be included in Ravenwood.

Bug: 292141694
Test: atest-dev CtsUtilTestCasesRavenwood
Change-Id: I8d49b34d916f7d2abcde9f3236f0bfc741218d37
diff --git a/core/java/android/util/Base64.java b/core/java/android/util/Base64.java
index 33cc5e3..92abd7c 100644
--- a/core/java/android/util/Base64.java
+++ b/core/java/android/util/Base64.java
@@ -26,7 +26,6 @@
  * href="http://www.ietf.org/rfc/rfc2045.txt">2045</a> and <a
  * href="http://www.ietf.org/rfc/rfc3548.txt">3548</a>.
  */
-@android.ravenwood.annotations.RavenwoodWholeClassKeep
 public class Base64 {
     /**
      * Default values for encoder/decoder flags.
diff --git a/core/java/com/android/internal/util/ArrayUtils.java b/core/java/com/android/internal/util/ArrayUtils.java
index 54f1cbf..686e1fc 100644
--- a/core/java/com/android/internal/util/ArrayUtils.java
+++ b/core/java/com/android/internal/util/ArrayUtils.java
@@ -21,11 +21,10 @@
 import android.compat.annotation.UnsupportedAppUsage;
 import android.os.Build;
 import android.util.ArraySet;
+import android.util.EmptyArray;
 
 import dalvik.system.VMRuntime;
 
-import libcore.util.EmptyArray;
-
 import java.io.File;
 import java.lang.reflect.Array;
 import java.util.ArrayList;
diff --git a/framework-minus-apex-ravenwood-policies.txt b/framework-minus-apex-ravenwood-policies.txt
index 6ffa338..6fd346f 100644
--- a/framework-minus-apex-ravenwood-policies.txt
+++ b/framework-minus-apex-ravenwood-policies.txt
@@ -40,6 +40,12 @@
 class android.util.JsonWriter stubclass
 class android.util.MalformedJsonException stubclass
 
+# Base64
+class android.util.Base64 stubclass
+class android.util.Base64DataException stubclass
+class android.util.Base64InputStream stubclass
+class android.util.Base64OutputStream stubclass
+
 # Data Holders
 class android.util.MutableFloat stubclass
 class android.util.MutableShort stubclass
@@ -47,6 +53,7 @@
 class android.util.MutableByte stubclass
 class android.util.MutableChar stubclass
 class android.util.MutableDouble stubclass
+class android.util.Pair stubclass
 class android.util.Range stubclass
 class android.util.Rational stubclass
 class android.util.Size stubclass